1. Field of the Invention
The present invention relates to a test handler for supporting a test of semiconductor devices. More particularly, the present invention relates to an arrangement structure and an operation method of a posture changing unit of the test handler for changing the posture of a test tray.
2. Description of the Related Art
In general, a test handler supports a test of semiconductor devices (hereinafter, referred to as a ‘device’) manufactured through a predetermined manufacturing process, and sorts and loads the devices on user trays according to the test results. To sort the devices according to the test results, the test handler circulates a test tray against a tester head. The test handler is classified into an under head docking type and a side docking type according to a docking method between the test handler and a tester.
The side docking type test handler transfers devices from user trays to a horizontal posture test tray, changes the horizontal posture of the device-loaded test tray into the vertical posture, pre-heats/pre-cools the vertical posture test tray, and connects the vertical posture test tray to a vertical posture tester head. After the test, the test handler restores the vertical posture test tray to the normal temperature, changes the vertical posture of the test tray to the horizontal posture, and sorts and unloads the devices to the user tray according to the test results.
As publicly known, the side docking type test handler includes a loading unit, a vertical posture changing unit, a soak chamber, a test chamber, a de-soak chamber, a horizontal posture changing unit and an unloading unit. The structure of the test handler will now be briefly explained with reference to FIG. 12.
The loading unit 1120 transfers and loads devices loaded on user trays 1110 to a horizontal posture test tray.
The vertical posture changing unit 1130 is positioned in the upward direction of the soak chamber 1200, and changes the horizontal posture of the test tray into the vertical posture before supplying the test tray to the soak chamber 1200.
The soak chamber 1200 sequentially receives the test trays posture-changed into the vertical posture by the vertical posture changing unit 1130, and has a temperature environment for pre-heating/pre-cooling the devices loaded on each test tray. The test trays entering the soak chamber 1200 are translated closely to the test chamber 1100 with the vertical posture. During the translation, the devices loaded on the test trays are sufficiently pre-heated/pre-cooled.
The test chamber 1100 is installed to the test handler, in which the devices loaded on the test tray supplied from the soak chamber 1200 can be tested by a tester. For this, the test chamber 1100 has a temperature environment for testing the devices.
The de-soak chamber 1300 (restoring chamber) restores the heated or cooled devices to the normal temperature.
The horizontal posture changing unit 1230 is positioned in the upward direction of the de-soak chamber 1300 for changing the vertical posture of the test tray transferred from the de-soak chamber 1300 to the horizontal posture.
The unloading unit 1260 sorts and unloads (transfers and loads) the test-completed devices to user trays 1310 according to the test results.
With the recent increase in demand and production of devices, the test handler has been developed to increase the number of devices tested at a time by loading many devices on one test tray, namely, to enlarge the test tray to carry many devices. If the test tray is two-dimensionally enlarged to test many devices at a time, the space for changing the posture of the test tray is three-dimensionally enlarged.
In the side docking type test handler, the posture changing unit is installed in the upward direction of the soak chamber, and the test tray posture-changed by the posture changing unit is transferred in the downward direction and received in the soak chamber. When the side. docking type test handler adopts the enlarged test tray, the whole size of the test handler must be increased more than the enlarged size of the test tray by a few times in order to prevent interferences between the space for changing the posture of the test tray and the wall of the soak chamber. However, the test handler can be put into practical use only under a predetermined external appearance standard (such as width, length and height). As a result, in relation to the enlargement tendency of the test tray, the test handler has already reached the maximum size.
Furthermore, since the pre-heating/pre-cooling process is started after the vertical posture change of the test tray, the soak chamber must have a relatively long translation section. It is thus difficult to reduce the length of the test handler and the pre-heating/pre-cooling time.